An improvement of the Berry--Esseen inequality with applications to Poisson and mixed Poisson random sums

By a modification of the method that was applied in (Korolev and Shevtsova, 2009), here the inequalities $$\rho(F_n,\Phi)\le\frac{0.335789(\beta^3+0.425)}{\sqrt{n}}$$ and $$\rho(F_n,\Phi)\le \frac{0.3051(\beta^3+1)}{\sqrt{n}}$$ are proved for the uniform distance $\rho(F_n,\Phi)$ between the standard normal distribution function $\Phi$ and the distribution function $F_n$ of the normalized sum of an arbitrary number $n\ge1$ of independent identically distributed random variables with zero mean, unit variance and finite third absolute moment $\beta^3$. The first of these inequalities sharpens the best known version of the classical Berry--Esseen inequality since $0.335789(\beta^3+0.425)\le0.335789(1+0.425)\beta^3<0.4785\beta^3$ by virtue of the condition $\beta^3\ge1$, and 0.4785 is the best known upper estimate of the absolute constant in the classical Berry--Esseen inequality. The second inequality is applied to lowering the upper estimate of the absolute constant in the analog of the Berry--Esseen inequality for Poisson random sums to 0.3051 which is strictly less than the least possible value of the absolute constant in the classical Berry--Esseen inequality. As a corollary, the estimates of the rate of convergence in limit theorems for compound mixed Poisson distributions are refined.Comment: 33 page

Sex differences in volume overload in skinned fibers

Background The impact of sex on cardiac morphology and function in chronic volume overload has been described in detail. However, the relation between sex and contractile properties at the actin-myosin level has not been well defined. Therefore, we evaluated the influence of sex on the contractile capacities of patients with chronic volume overload. Methods In 36 patients (18 males, 65 ± 9 years; 18 females, 65 ± 13 years) scheduled for elective mitral valve surgery due to severe mitral regurgitation (MR) with preserved left ventricular function, right auricle samples were obtained prior to extracorporal circulation. The fibers were prepared and skinned and exposed to a gradual increase in the calcium concentration (from pCa of 6.5–4.0) for calcium-induced force-developing measurements. Calcium sensitivity was also measured and recorded. Results The pCa-force relationship of the fibers obtained from males and females was significantly different, with the force values of the female fibers greater than those of male fibers at maximum calcium concentrations (pCa of 4.0: 3.6 ± 0.3 mN versus 3.2 ± 0.4 mN, p 0.02) and pCa of 4.5 2.6 ± 0.6 versus 2.0 ± 0.5, p 0.002). In contrast, the force values of female fibers were lower at mean calcium concentrations compared to those of male fibers (at 5.5 and pCa of 6.0: 1.0 ± 0.3 mN versus 1.2 ± 0.5 mN, p 0.04; 0.61 ± 0.05 versus 0.88 ± 0.09, p 0.04). Calcium sensitivity was observed at pCa of 5.0 in females and pCa of 4.5 in males. Conclusion This study demonstrated that female fibers from patients exposed to chronic volume overload developed higher force values at a given calcium concentration compared to fibers from male patients. We assume that female patients might tap the full force potential, which is required when exposed to the highest calcium concentrations in our experimental cycle. The calcium sensitivity among genders was significantly different, with the results suggesting that males have higher calcium sensitivity and might compensate for lower force values at maximal calcium concentrations by a higher affinity for calcium. Hence, female patients with MR seem to work more “energy efficient”

Impact of estradiol, testosterone and their ratio on left and right auricular myofilament function in male and female patients undergoing coronary artery bypass grafting

Abstract Background The impact of sex hormones on right and left auricular contractile apparatus function is largely unknown. We evaluated the impact of sex hormones on left and right heart contractility at the level of myocardial filaments harvested from left and right auricles during elective coronary artery bypass surgery. Methods 150 patients (132 male; 18 female) were enrolled. Preoperative testosterone and estradiol levels were measured with Immunoassay. Calcium induced force measurements were performed with left- and right auricular myofilaments in a skinned fiber model. Correlation analysis was used for comparison of force values and levels of sex hormones and their ratio. Results Low testosterone was associated with higher top force values in right-sided myofilaments but not in left-sided myofilaments for both sexes (p = 0.000 in males, p = 0.001 in females). Low estradiol levels were associated with higher top force values in right-sided myofilaments (p 0.000) in females and only borderline significantly associated with higher top force values in males (p 0.056). In females, low estradiol levels correlated with higher top force values in left sided myofilaments (p 0.000). In males, higher Estradiol/Testosterone ratio (E/T ratio) was only associated with higher top force values from right auricular myofilaments (p 0.04) In contrast, in females higher E/T ratio was associated with lower right auricular myofilament top force values (p 0.03) and higher top force values in left-sided myofilaments (p 0.000). Conclusions This study shows that patients’ comorbidities influence left and right sided contractility and may blur results concerning influence of sex hormones if not eliminated. A sex hormone dependent influence is obvious with different effects on the left and right ventricle. The E/T ratio and its impact on myofilament top force showed divergent results between genders, and may partially explain gender differences in patients with cardiovascular disease

Field evaluation of photothermal models for predicting the date of flowering and maturity in cover legumes using photothermal models

Lack of information about the specific environmental adaptation of cover crop species remains a serious constraint in the efficient design of agronomic experiments examining options for more suitable and more sustainable management of hillside farming systems in the tropics. Predictive models of crop phenology for cover crop species exist but how robust these are for legume cover crop species is largely unproven. We determined the predictive ability of phenological models, derived from glasshouse studies and driven by temperature and photoperiod, across a diverse range of cover crop genotypes and tropical hillside environments. The models were designed to predict the duration from germination to first flowering, and from first flowering to first pod maturity. Seeds of eleven legume species of cover and/or green manure crops collected from different hillside locations world-wide were sown in two groups of nurseries (tropical short-day plants in early summer and sub-tropical long-day plants in early winter) at Kabale and Namulonge in Uganda, Godavari and Lumie in Nepal, Cochabamba in Bolivia, Zamorano in Honduras, and Valenca in Brazil. Dates of sowing, first flowering and first pod maturity were taken and daily temperature data were recorded at each site. Similar observations for the same genotypes were available from independent experiments conducted at Islamabad, Pakistan, Hattiban, Nepal and at three locations in Cyprus. Model predictions were compared with field observations. The proportion of variation accounted for in the period from sowing to first pod maturity was 88% and 89% for the short-day and the long-day groups of genotypes, respectively. Likewise, the average difference from sowing to pod maturity between the model predictions and the field observations was 6.3% and 7.9% for the combined short-day species and the combined long-day species, respectively. It is clear that the model predictions, for this dataset at least, are sufficiently robust to serve as a filter for determining the environmental suitability of germplasm

Novel amphiphilic corannulene additive for moisture-resistant perovskite solar cells

The addition of amphiphilic triethylene glycol based corannulene molecules provides multiple Lewis basic sites that assist in perovskite grain growth, and improve the charge carrier collection and moisture resistance of perovskite solar cells. This study paves the way for utilization of more molecules from corannulene families in perovskite research.Agency for Science, Technology and Research (A*STAR)Ministry of Education (MOE)National Research Foundation (NRF)Submitted/Accepted versionThis research was supported by NTU start-up grants (M4081866, M4081566), Ministry of Education (MOE) under AcRF Tier 2 grant (2018-T2-1-075), A*STAR AME IAF-ICP Grant (No. I1801E0030), A*STAR AME IRG A1883c0006 and National Research Foundation, Prime Minister’s Office, Singapore, under Energy Innovation Research Program and Intra-CREATE collaborative grant (NRF2015EWT-EIRP003-004, NRF2018-ITC001-001 and Solar CRP: S18-1176-SCRP)